var year =prompt("请输入年份：");
var  month =prompt("请输入月份：");

year =Number(year);
month =Number(month);

function runNian(year) {
    if (year %400 ===0|| (year%4===0&&year%100!==0)){
        return true;
    }else {
        return false;
    }
}


var day = document.querySelector("#day");

var days =0;
for(var i=1980; i<year;i++){
    if (runNian(i)){
        days +=366;
    }else {
        days +=365;
    }
}


for (var k =1;k<month;k++){
    switch (k){
        case  1:
            days +=31;
            break;
        case 2:
            if (runNian(year)){
                days+=29;
            }else {
                days+=28;
            }
            break;
        case  3:
            days +=31;
            break;
        case  4:
            days +=30;
            break;
        case  5:
            days +=31;
            break;
        case  6:
            days +=30;
            break;
        case  7:
            days +=31;
            break;
        case  8:
            days +=31;
            break;
        case  9:
            days +=30;
            break;
        case  10:
            days +=31;
            break;
        case  11:
            days +=30;
            break;
        case  12:
            days +=31;
            break;
    }
}



days +=2;
console.log(days);



var start = days % 7;
console.log(start);


var prevDay =0;
switch (month -1){
    case  1:
        prevDay +=31;
        break;
    case 2:
        if (runNian(year)){
            prevDay+=29;
        }else {
            prevDay+=28;
        }
        break;
    case  3:
        prevDay+=31;
        break;
    case  4:
        prevDay +=30;
        break;
    case  5:
        prevDay +=31;
        break;
    case  6:
        prevDay +=30;
        break;
    case  7:
        prevDay +=31;
        break;
    case  8:
        prevDay +=31;
        break;
    case  9:
        prevDay +=30;
        break;
    case  10:
        prevDay +=31;
        break;
    case  11:
        prevDay +=30;
        break;
    case  12:
        prevDay +=31;
        break;
}


var thisDay =0;
switch (month){
    case  1:
        thisDay +=31;
        break;
    case 2:
        if (runNian(year)){
            thisDay+=29;
        }else {
            thisDay+=28;
        }
        break;
    case  3:
        thisDay +=31;
        break;
    case  4:
        thisDay +=30;
        break;
    case  5:
        thisDay +=31;
        break;
    case  6:
        thisDay +=30;
        break;
    case  7:
        thisDay +=31;
        break;
    case  8:
        thisDay +=31;
        break;
    case  9:
        thisDay +=30;
        break;
    case  10:
        thisDay +=31;
        break;
    case  11:
        thisDay +=30;
        break;
    case  12:
        thisDay +=31;
        break;
}



for(var j=prevDay -start+1;j <=prevDay;j++){
    day.innerHTML +='<span class="h">' +j+'</span>';
}

var d=new Date().getDate();
for (s=1;s<=thisDay;s++){
    if (s==d){
        day.innerHTML +='<span class="today">' + s +'</span>';
    }else {
        day.innerHTML +='<span>' +s+'</span>';
    }
}
var num =42;
var endDay =num-start-thisDay;
for(var e =1;e<=endDay;e++){
    day.innerHTML +='<span class="h">' +e+'</span>';
}
document.querySelector("#nian").innerHTML =year;
document.querySelector("#yue").innerHTML =month;